Question ALL fans turn off just before post

Oct 4, 2021
Hi, I just came home to a pretty strange issue. All fans including the CPU fans will spin up upon pressing the power button but they all turn off right before the post beep. The lights on the fans stay on but the fans won't spin. Last time I had this issue was because I had forgotten a cable when installing a new CPU, but I checked and everything seems to be plugged in. I also noticed that my BIOS settings randomly reset, whether or not that links to the fan issue I'm not sure. BIOS reads the temperature as -55 degrees, and the CPU is severely underclocking when I boot into Windows so as to not fry itself.

Any ideas? I'm thinking I may have to get a new PSU but I'm not sure.